1. Description of Related Art
Generally, video data and audio data are recorded on optical disks, such as DVDs (Digital Versatile Discs), and users who wish to view video recordings can reproduce the video data and the audio data from the optical disks. However, since individually, the storage capacity of optical disks is limited, not all audio data, such as two-channel stereo audio data, Dolby digital (trademark of Dolby Laboratories Corp., in the United States) 5.1-channel audio data, DTS (Digital Theater System) high-quality audio data, multi-language audio data and audio data for commentaries, are actually recorded. Suffice it to say, therefore, that optical disk users can not reproduce audio data that is not recorded when desired audio data are not available on an optical disk.
There is a conventional example wherein multiple sets of video information are accumulated, using time division multiplexing, or arbitrary sets of accumulated video information are output in real time, or wherein one or more sets of video information are accumulated and, at the same time, one or more arbitrary sets of accumulated video information are output (see, for example, JP-A-10-243352).
There is another conventional example wherein first MPEG data are read from a first recording medium, and based on the MPEG data, position information is obtained that indicates the positions of the preceding and succeeding data groups of a specified data group of first MPEG data, and wherein the position information is added to a position, determined for the first MPEG data, for generating second MPEG data, and the second MPEG data are recorded on a second recording medium (see, for example, JP-A-2002-218393).